Methods related to packaged modules having tuned shielding

ABSTRACT

Disclosed are devices and methods related to radio-frequency (RF) shielding of RF modules. In some embodiments, tuned shielding can be achieved by utilizing different structures and/or arrangements of shielding-wirebonds to increase shielding in areas where needed, and to decrease shielding where not needed. Such tuning of shielding requirements can be obtained by measuring RF power levels at different locations of a module having a given design. Such tuned RF shielding configurations can improve the overall effectiveness of shielding, and can also be more cost effective to implement.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional of U.S. application Ser. No. 13/543,084filed Jul. 6, 2012 entitled RADIO-FREQUENCY MODULES HAVING TUNEDSHIELDING-WIREBONDS, which claims priority to and the benefit of thefiling date of U.S. Provisional Application No. 61/506,002 filed Jul. 8,2011 entitled WIREBOND DEVICES AND METHODOLOGIES FOR PROVIDINGRADIOFREQUENCY ISOLATION, the benefits of the filing dates of which arehereby claimed and the disclosures of which are hereby expresslyincorporated by reference in their entirety.

BACKGROUND

1. Field

The present disclosure generally relates to shielding of radio-frequencydevices such as modules used in wireless devices.

2. Description of the Related Art

Radio-frequency (RF) is a common term for a range of frequency ofelectromagnetic radiation typically used to produce and detect radiowaves. Such a range can be from about 30 kHz to 300 GHz. In somesituations, operation of an electronic device can adversely affectand/or be adversely affected by undesired RF signals.

To address such problems, RF shielding structures can be provided toreduce the effects of the undesired RF signals. Such RF shieldingtypically operate based on what is commonly referred to as a Faradaycage principle.

SUMMARY

According to a number of implementations, the present disclosure relatesto a radio-frequency (RF) module that includes a packaging substrateconfigured to receive a plurality of components. The module furtherincludes a plurality of RF components configured to facilitateprocessing of an RF signal. The module further includes an RF shielddisposed relative to at least one of the RF components. The RF shield isconfigured to provide selective shielding capability based on either orboth of an RF emission pattern and height dimensions associated with theRF components.

In some embodiments, the plurality of RF components can include a poweramplifier die. In some embodiments, the RF shield can include a segmentconfigured to provide a base-level of shielding. The selective shieldingcapability can be provided by an enhanced segment of the RF shieldconfigured to provide an enhanced level of shielding that is greaterthan the base-level.

In some embodiments, the enhanced segment can include a higher densityof shielding-wirebonds relative to a density associated with thebase-level of shielding.

In some embodiments, the enhanced segment can include a cornershielding-wirebond disposed at a corner of the RF shield, with thecorner shielding-wirebond being configured to provide additionalshielding at the corner.

In some embodiments, the enhanced segment can include one or moreshielding-wirebonds oriented so that planes associated with theshielding-wirebonds are at a non-zero angle relative to a linerepresentative of the enhanced segment. The non-zero angle can beapproximately 90 degrees.

In some embodiments, the enhanced segment can include a first row ofshielding-wirebonds offset laterally from a second row ofshielding-wirebonds. The shielding-wirebonds of the first row can bearranged in a stagger configuration relative to the shielding-wirebondsof the second row. One of the first and second rows can be part of thesegment that provides the base-level of shielding.

In some embodiments, the enhanced segment can include one or moreassemblies of shielding-wirebonds. Each assembly can include a firstshielding-wirebond and a second shielding-wirebond that is nested withinan area defined by the first shielding-wirebond. The secondshielding-wirebond can be dimensioned to provide RF shielding within thearea defined by the first shielding-wirebond. The area defined by thefirst shielding-wirebond can have an aspect ratio of about 1.

In some embodiments, the RF shield can include a segment configured toprovide shielding between a first region and a second region, with bothof the first and second regions being on the module. In someembodiments, the RF shield can include a segment configured to provideshielding between a region on the module and a location outside of themodule. In some embodiments, the RF shield can partially surround the atleast one RF component. In some embodiments, RF shield can fullysurround the at least one RF component. In some embodiments, the modulecan further include a conductive layer disposed over the at least one RFcomponent and electrically connected to an upper portion of the RFshield. In some embodiments, the module can further include a groundplane disposed below the at least one RF component and electricallyconnected to a lower portion of the RF shield. The conductive layer, theRF shield, and the ground plane can provide a shielded volume for the atleast one RF component.

In some implementations, the present disclosure relates to a method forfabricating a radio-frequency (RF) module. The method includes providinga packaging substrate configured to receive a plurality of components.The method further includes mounting a plurality of RF componentsconfigured to facilitate processing of an RF signal. The method furtherincludes forming an RF shield relative to at least one of the RFcomponents. The RF shield is configured to provide selective shieldingcapability based on either or both of an RF emission pattern and heightdimensions associated with the RF components.

In a number of implementations, the present disclosure relates to awireless device that includes an antenna and a module in communicationwith the antenna. The module is configured to facilitate either or bothof transmission and reception of RF signals through the antenna. Themodule includes a packaging substrate configured to receive a pluralityof components. The module further includes a plurality of RF componentsconfigured to facilitate processing of an RF signal. The module furtherincludes an RF shield disposed relative to at least one of the RFcomponents. The RF shield is configured to provide selective shieldingcapability based on either or both of an RF emission pattern and heightdimensions associated with the RF components.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 schematically depicts a radio-frequency (RF) module that includesa tuned RF shield having one or more features as described herein.

FIG. 2 shows a process that can be implemented to configure the tuned RFshield of FIG. 1.

FIGS. 3A-3L and 4A-4L show an example of the tuning process of FIG. 2,where one or more locations on a module can be identified and selectedto be provided with, for example, additional shielding.

FIGS. 5A-5D and 6A-6D show another example of the tuning process of FIG.2.

FIG. 7A schematically depicts a tuning configuration where one or moreRF emissions from within a given area are identified, and whereshielding capabilities are adjusted accordingly.

FIG. 7B schematically depicts a tuning configuration where one or moreRF emissions from outside a given area are identified, and whereshielding capabilities are adjusted accordingly.

FIG. 8 shows a more generalized configuration that can cover theexamples of FIGS. 7A and 7B, where a shielding configuration betweenfirst and second regions can be adjusted to provide RF isolation betweenthe two regions in an effective manner.

FIGS. 9A-9C show non-limiting examples of wirebond structures that canbe utilized to facilitate various tuned RF shielding examples describedherein.

FIG. 10 shows an example configuration where shielding capability isgenerally uniform around a periphery of a module.

FIG. 11 shows an example configuration where shielding capability canvary based on different wirebond densities along a given shielding line.

FIGS. 12A and 12B show example configurations where shielding capabilitycan be increased for one or more corner regions.

FIGS. 13A and 13B show an example configuration whereshielding-wirebonds can be oriented to be generally perpendicular to agiven shielding line that can effectively provide depth in shielding.

FIG. 14 shows an example configuration that is a variation of theexample of FIGS. 13A and 13B, where shielding-wirebonds can be angled toprovide an increase in effective density of shielding structures.

FIGS. 15A and 15B show non-limiting examples of staggered configurationformed by first and second rows of wirebonds.

FIG. 16 shows that a section having such a staggered configuration canyield a section with increased shielding capability.

FIG. 17 shows example shielding-wirebonds dimensioned to be taller thanan RF device and its connection-wirebonds to provide effective RFshielding.

FIG. 18 shows an example shielding configuration where a shieldingstructure can be provided to accommodate a relatively tall RF device,where the shielding structure can include a smaller shielding-wirebondnested within a larger shielding-wirebond to provide shielding for theincreased shielding area.

FIG. 19 shows that in some embodiments, the shielding structure of FIG.18 can be provided partially or fully around the tall RF device.

FIGS. 20A-20C show non-limiting examples of shielding configurationsthat can be implemented on modules using one or more features describedherein.

FIG. 21 shows an example wireless device having a shielded module asdescribed herein.

DETAILED DESCRIPTION OF SOME EMBODIMENTS

The headings provided herein, if any, are for convenience only and donot necessarily affect the scope or meaning of the claimed invention.

Disclosed herein are various devices and methods for providingradio-frequency (RF) isolation or shielding for an active or a passiveRF device. For the purpose of description, it will be understood that RFcan include electromagnetic signals having a frequency or a range offrequencies associated with wireless devices. RF can also includeelectromagnetic signals that radiate within an electronic device,whether or not such an electronic device operates as a wireless device.RF can also include signals or noises typically associated withelectromagnetic interference (EMI) effects.

For the purpose of description it will be understood that such an RFdevice can include a device configured to operate at an RF range tofacilitate transmitting and/or receiving of RF signals, and a devicethat can influence another device by, or be influenced by, RF signals ornoises. Non-limiting examples of such an RF device can include asemiconductor die with or without an RF circuitry. Non-limiting examplesof such an RF-related device can include discrete devices such asinductors and capacitors, and even a length of a conductor.

For the purpose of description, it will be understood that the termsisolation and shielding can be used interchangeably, depending on thecontext of usage. For example, an RF device being shielded can include asituation where an RF signal from another source is being partially orfully blocked. In another example, an RF device being isolated caninclude a situation where an RF signal (e.g., noise or activelygenerated signal) is being partially or fully blocked from reachinganother device. Unless the context of usage specifically statesotherwise, it will be understood that each of the terms shielding andisolation can include either or both of the foregoing functionalities.

FIG. 1 schematically depicts an RF module 100 having a tuned RF shield102. Various examples of how such a tuned RF shield can be configuredare described herein in greater detail. For the purpose of description,it will be understood that a “tuned” RF shield can be based on, forexample, localized radiated power levels, mechanical considerationsassociated with shield structures, manufacturing considerations, or anycombination thereof. In some embodiments, such a tuned RF shield canprovide different shielding capabilities along a given shielding segmentor perimeter.

FIG. 2 shows a process 110 that can be implemented to tune an RF shieldfor a given RF module configuration. In block 112, an RF moduleconfiguration can be provided. In block 114, RF shielding-wirebonds canbe tuned based on the module configuration. In block 116, the tuned RFshielding-wirebonds can be formed for the module.

FIGS. 3-6 show examples of the tuning process described in reference toFIG. 2. FIGS. 7-19 show examples of shielding-wirebonds that caneffectuate one or more tuned configurations resulting from the tuningprocess.

In FIG. 3A, an example power amplifier (PA) module 120 is shown toinclude a high-band PA circuit that is operating at approximately 1.71GHz, and a low-band PA circuit that is not operating. Both of thehigh-band and low-band circuits are shown to be surrounded byshielding-wirebonds 122 indicated as 1-18. The wirebonds 122 aregenerally the same, and are spaced apart generally uniformly in a givenside. In each of the high-band and low-band circuits, an input to the PAcircuit is near the bottom of the region (dashed region), and an outputof the PA circuit is near the top of the region.

FIG. 4A shows a segmented contour plot of radiated power for the regionsurrounded by the eighteen shielding-wirebonds 122. Darker shadedsegments correspond to lower radiated power levels, and lighter shadedsegments correspond to higher radiated power levels. The exampleconfiguration of FIGS. 3A and 4A is designated as a controlconfiguration where all of the eighteen example shielding-wirebonds 122are present.

FIGS. 3B-3L and 4B-4L correspond to configurations where one of theeighteen shielding wirebonds 122 is removed. Table 1 lists additionaldetails of such configurations, as well as the control configuration ofFIGS. 3A and 4A.

TABLE 1 FIGS. Wirebond removed Changes in radiated power level 3A, 4ANone N/A 3B, 4B  #1 Minimal 3C, 4C  #3 Minimal 3D, 4D  #5 Minimal 3E, 4E #9 Minimal 3F, 4F #12 Minimal 3G, 4G #13 Significant 3H, 4H #14Significant 3I, 4I #15 Moderate 3J, 4J #16 Moderate 3K, 4K #17 Moderate3L, 4L #18 ModerateIn Table 1, changes in radiated power level can be categorized asfollows: “minimal,” where the changes result in levels that are within agiven specification, “moderate,” where the changes are worse, but theresulting levels are still within specification, and “significant,”where the changes result in levels that are out of specification at oneor more locations.

FIGS. 5A-5D and 6A-6D correspond to configurations where one of theeighteen shielding wirebonds 122 is removed, with the high-band PAcircuit not operating, and the low-band PA circuit operating atapproximately 0.824 GHz. Table 2 lists additional details of suchconfigurations.

TABLE 2 FIGS. Wirebond removed Change in radiated power level 5A, 6A #3Minimal 5B, 6B #5 Minimal 5C, 6C #8 Minimal 5D, 6D #9 MinimalIn Table 2, changes in radiated power levels are shown to be less thanthose associated with the high-band example of Table 1.

Based on the foregoing examples, some observations can be made. Forexample, in the high-band operation configuration, RF shieldingeffectiveness is relatively low near the output area. Removal of eitherof shielding-wirebonds #13 and #14 results in the RF shieldingperformance being out of specification at one or more locations. Removalof any of shielding-wirebonds #15 to #18 also degrade RF shieldingperformance somewhat, but within specification.

For the low-band operation configuration, RF shielding performance isless sensitive to removal of shielding-wirebonds than that of theforegoing high-band operation.

From the foregoing examples described in reference to FIGS. 3-6, one cansee that for a given module configuration, shielding areas that aresubject to significant shielding performance changes can be identified.Similarly, shielding areas that are not subject to significant shieldingperformance changes can also be identified. In some implementations, thefirst of these two shielding areas can be reinforced to provide greatershielding, and the second shielding areas can be configured to providelesser shielding (e.g., by removing shielding-wirebond(s)).

FIG. 7A schematically depicts an example tuned RF shield 102 having oneor more portions where shielding capability is increased, and one ormore portions where shielding capability is decreased. In someembodiments, such increase and/or decrease in shielding capability canbe relative to a base shielding configuration 160 (e.g., FIG. 10).

In FIG. 7A, a relatively high level of RF emission is depicted as 150,and it is desired that such emission be prevented from leaving the areadefined by the RF shield 102. To facilitate such shielding, increasedshielding capability can be provided to segments indicated as 162, 164,and 166. Among such segments, there can be one or more levels ofincrease shielding capabilities. For example, segments 162 and 166 canbe configured to provide a shielding capability that is greater thanthat of the base level 160; and segment 164 can be configured to provideeven greater shielding capability than that of segments 162, 166.

Also in FIG. 7A, another example of a relatively high level of RFemission is depicted as 152. To facilitate shielding of such anincreased emission level, a segment indicated as 168 can be provided.Examples of such enhanced shielding-capability configurations (162, 164,166, 168) are described herein in greater detail.

FIG. 7A also shows that for areas where emission levels are relativelylow, shielding capability can be reduced without significantly impactingthe performance of circuits and components within the RF shield 102. Forexample, segments of the base level shielding 160 that would be locatedat locations 170 can be removed. In some implementations, such removalof shielding-wirebonds can reduce time and cost associated withfabrication of modules.

In the example described in reference to FIG. 7A, the RF shield 102generally defines an inside region and an outside region. The exampleemissions 150, 152 are described in the context of originating from theinside and prevented from radiating to locations on the outside. It willbe understood, however, that shielding segments can also inhibit RFsignal or noise from entering the inside from the outside.

FIG. 7B shows that tuning of an RF shield 102 can also be based on oneor more emission sources located outside of the RF shield 102. Unlikethe example of FIG. 7A (where emission locations are generally fixed)emission-source locations outside of the RF shield 102 may or may not befixed. For the purpose of description, suppose that such a location isfixed (e.g., a component fixed outside of a module), and such anemission 180 attempting to enter the RF shield 102 is localized. One ormore shielding segments 182 can be configured to provide increasedshielding capability in manners similar to those described in referenceto FIG. 7A.

In some implementations, increased shielding capability segments can bebased on known emission sources that are located inside and outside of aregion defined by an RF shield 102.

In the examples described in reference to FIGS. 7A and 7B, regionsgenerally delineated by an RF shield 102 are referred to as “inside” and“outside.” Such terms can be suitable for describing configurationswhere the RF shield 102 substantially encloses a given area. However, itwill be understood that one or more features described herein do notrequire that an RF shield enclose an area being shielded.

FIG. 8 shows that in some implementations, an RF shield 102 can preventRF signals from passing between first and second regions. In the exampleshown, the RF shield 102 is depicted as a line having a base-levelshield 190. Based on such a shield (190), one or more segments (e.g.,segment 192) having increased shielding capability can be provided.Also, one or more segments can be configured with reduced shieldingcapability (e.g., shielding segment removed from location 194).

It will be understood that although the RF shield 102 is depicted as astraight line, other shapes (e.g., curved) can also be utilized.

In some implementations, various RF shield segments and/or linesdescribed herein can be based on a number of shielding-wirebond shapes.FIGS. 9A-9C show non-limiting examples of such shielding wirebonds. InFIG. 9A, a shielding-wirebond 50 having a deformable configuration isshown to be formed on bond pads 52 a, 52 b that are on a packagingsubstrate 54 (e.g., laminate substrate). Additional details concerningsuch a wirebond configuration are available in International PublicationNo. WO 2010/014103 (International Application No. PCT/US2008/071832,filed on Jul. 31, 2008, titled “SEMICONDUCTOR PACKAGE WITH INTEGRATEDINTERFERENCE SHIELDING AND METHOD OF MANUFACTURE THEREOF”) which isincorporated herein by reference in its entirety.

In FIG. 9B, an arch shaped shielding-wirebond 50 is shown to be formedon bond pads 52 a, 52 b that are on a packaging substrate 54 (e.g.,laminate substrate). Additional details concerning such a wirebondconfiguration are available in U.S. Publication No. US 2007/0241440(U.S. application Ser. No. 11/499,285, filed on Aug. 4, 2006, titled“OVERMOLDED SEMICONDUCTOR PACKAGE WITH A WIREBOND CAGE FOR EMISHIELDING”) which is incorporated herein by reference in its entirety.

FIG. 9C shows that in some embodiments, shielding-wirebonds do not needto be curved or have ends that begin and end on the packaging substrate.A wirebond structure 50 that begins on the packaging substrate 54 andends at a location above the packaging substrate 54 is shown to beformed on a bond pad 52. Additional details concerning such a wirebondconfiguration are available in the above-referenced U.S. Publication No.US 2007/0241440.

FIG. 10 shows an example of a base-level shielding capability that canbe formed by a plurality of shielding-wirebonds 50 such as one or moreof the examples of FIGS. 9A-9C. Such wirebonds are shown to be generallyaligned along a perimeter that surrounds an RF device 16. FIGS. 11-19show examples of RF shields that can provide additional or lessshielding capability compared to, for example, the base-level shieldingconfiguration of FIG. 10.

FIG. 11 shows an example shielding configuration 200 where a pluralityof shielding-wirebonds 50 are generally aligned along a shielding line.In this example, spacing between the wirebonds 50 and/or lateraldimensions of such wirebonds can be adjusted to provide different RFshielding characteristics. For example, suppose that a segment indicatedas 190 has wirebonds 50 separated by “s2” to yield a first wirebonddensity that provides a base-level shielding. Different shieldingcharacteristics can be provided by arranging the wirebonds 50 in a moredense (e.g., segment 192 with separation distance “s1”) arrangement, orin a less dense (e.g., one or more removed from location 194)arrangement. In some embodiments, such wirebond-density segments can bebased on locations of identified emission hotspots and frequenciesassociated with such emissions.

FIG. 12A shows an example configuration 210 that can be implemented toprovide a desired shielding configuration at a corner defined by twolines of wirebonds 50. A corner wirebond 212 is shown to be arrangedalong a direction that, for example, divides the corner into two equalor unequal parts. By way of an example, such a corner wirebond can beprovided if an emission hotspot is near the corner.

FIG. 12B shows that in some embodiments, such a cornershielding-wirebond 212 can be provided at one or more corners of ashielding configuration 214 where wirebonds 50 generally surround an RFdevice 16 (e.g., in a rectangular manner). For each side of therectangle, a number of wirebonds 50 can be oriented so that planesdefined by such wirebonds are generally aligned along the side of therectangle. The corner wirebonds 212 are shown to be positioned at eachof the corners so as to provide a narrower gap between the end wirebondsof the two adjacent sides. In the example shown in FIG. 12B, each of thecorner wirebonds is shown to be oriented such that its plane divides theangle defined by the corner. The dimensions of each wirebond andspacings between the wirebonds can be selected to provide a desired RFshielding functionality.

In an example configuration 220 of FIG. 13A, an RF device 16 is depictedas being surrounded by a plurality of wirebonds 222 in a rectangular boxshaped pattern. For each side of the rectangle, the wirebonds 222 can beoriented so that planes defined by the wirebonds are generallyperpendicular to the side of the rectangle. For example, one row ofperpendicular wirebonds 222 are shown to be perpendicular to a line 60representative of that side of the rectangle. The dimensions of eachwirebond and spacings between the wirebonds can be selected to provide adesired RF shielding capability.

FIG. 13B shows a side view of one of the wirebonds 222 of FIG. 13A.Although the wirebond 222 is depicted as a deformable wirebond (e.g.,FIG. 9A) other looped configurations (e.g., arch configuration of FIG.9B) can also be implemented. To the left of the wirebond 222 is the RFdevice 16 (e.g., inside). By placing the wirebond 222 in such a manner,an RF emission radiating from the RF device 16 can be encounter a firstportion 224 of the wirebond 222, as well as a second portion 226.Accordingly, the wirebond 222 can provide increased RF shieldingcapability.

FIG. 14 shows a configuration 230 that can be a variation to the exampledescribed in reference to FIGS. 13A and 13B. A plurality of wirebonds222 are shown to be arranged as a non-zero angle from a perpendicular ofa side line 60. In such a configuration, effective spacing betweenconductor features of two neighboring wirebonds can be “s2,” which isless than the wirebond-to-wirebond spacing of “s1.” The spacing s2 canbe less than s1 due to the angled configuration, in a situation where anRF emission incident on the line 60 (along a normal direction) canexperience the first portion of one wirebond 222 and the second portionof the neighboring wirebond 222. In some implementations, the amount ofangle and/or the direction of the angle can be selected based on one ormore locations of emission hotspots relative to the shielding segment230.

FIGS. 15A and 15B show that in some implementations, more than one rowof wirebonds can be provided. In an example configuration 240, first andsecond rows of wirebonds 50 are shown to be disposed relative to eachother in a staggered manner to provide an additional RF isolatingcapability. In the example shown, the two rows are shown to be separatedby a distance “s3.” Within the first row, the wirebonds 50 are shown tobe separated from each other by a spacing of “s1.” Within the secondrow, the wirebonds 50 are shown to be separated from each other by aspacing of “s2.”

In FIG. 15A, dimensions of the wirebonds in the first row, dimensions ofthe wirebonds in the second row, and the spacing parameters s1 to s3 canbe selected to yield a desired RF shielding capability.

In FIG. 15A, the gaps of the first row are shown to be generally coveredby the wirebonds of the second row. Other arrangements are alsopossible. For example, FIG. 15B shows an example configuration where thewirebonds of the two rows provide partial overlaps with each otherbeyond the gaps. Such an arrangement can be achieved by, for example,reducing the wirebond-to-wirebond spacings s1 and s2. Similar to FIG.15A, dimensions of the wirebonds in the first row, dimensions of thewirebonds in the second row, and the spacing parameters s1 to s3 can beselected to yield a desired RF shielding capability.

FIG. 16 shows that in some embodiments, the two-row example of FIG. 15can be implemented to yield an increased shielding segment 192. In theexample configuration 250, a first row can include a selected number ofwirebonds 50 that generally covers the desired length of increasedshielding (192). A second row of wirebonds 50′ can extend beyond thefirst row. The portion where the first and second rows overlap can bethe increased shielding segment 192, and the remainder of the second row(with the wirebonds 50′) can function as a base-level shield.

FIG. 17 shows a side view of a module having an RF device 16 (height“h1”) mounted on a packaging substrate 54. The RF device 16 can beconnected to the module by a plurality of connection-wirebonds, and onesuch wirebonds is shown as 48 having a height of “h2.” A plurality ofshielding-wirebonds 50 are shown to have a height of “h3,” and such aheight typically needs to be greater than h2 and h1 so that a conductivelayer 46 that provides RF shielding on top is in contact with theshielding-wirebonds 50 but not the connection-wirebonds 48.

In some module designs, a relatively tall component may need to beincluded, and shielding-wirebonds need to increase in heightaccordingly. FIG. 18 shows an example configuration 260 where the tallcomponent 266 (height “h4”) is mounted on a packaging substrate 54. Thetall component 266 is connected to the module by a plurality ofconnection-wirebonds 48 (height “h5”).

A shielding-wirebond 50 a having a height of “h6” is shown toelectrically connect a conductive layer 46 to bond pads 26 a which arein turn connected to one or more ground planes (not shown) in thepackaging substrate 54. When the height h6 is sufficiently large,shielding functionality for a given frequency may be degraded. Such adegradation can be particularly noticeable when an aspect ratio (w6/h6)of about 1 is desired for the shielding-wirebond 50 a. For example, ifthe height h6 is increased by a factor of two, the area under theshielding-wirebond 50 a increases by a factor of about four. Such alarge area can allow RF signals and noises through under somecircumstances.

To “plug” the relatively large area defined by the shielding-wirebond 50a, a second shielding-wirebond 50 b can be provided. In the exampleshown in FIG. 18, the second shielding-wirebond 50 b can be nestedwithin the area defined by the first shielding-wirebond 50 a, and itsdimensions can be selected so that the two shielding-wirebonds 50 a, 50b (collectively 262) provides a desired level of RF shieldingcapability. In some embodiments, the second shielding-wirebond 50 b canbe formed on one or more bond pads 26 b, and such bond pads (26 b) canbe interconnected with the bond pads 26 a for the firstshielding-wirebond 50 a. With such an interconnection between the firstand second shielding-wirebonds 50 a, 50 b, the second shielding-wirebond50 b does not need to be connected directly to the conductive layer 46.

FIG. 19 shows an example configuration 270 where a tall RF device 266 isshielded by a plurality of shielding assemblies 262 of FIG. 18. Suchshielding assemblies 262 can partially or fully enclose the RF device266.

FIGS. 20A-20C show examples of how tuned RF shields 102 having one ormore features described herein can be implemented in a module 300 indifferent manners. As described herein, such tuned RF shields 102 caninclude one type of shielding-wirebond structures, or different segmentshaving different RF shielding properties.

In FIG. 20A, a tuned RF shield 102 is shown to be formed near theperimeter of a module 300 to substantially enclose most of the module'sarea. Components such as one or more dies 302 and one or moresurface-mount devices (SMDs) mounted on such an enclosed area canbenefit from the RF shielding properties of the RF shield 102.

In FIG. 20B, a tuned RF shield 102 is shown to be formed around onedevice 310 mounted on a module 300, but not around another device 312.Such a configuration can be implemented if the second device 312, forexample, does not produce RF emissions and is generally not susceptibleto interference from RF signals or noises. Such a configuration canreduce the amount of shielding-wirebonds utilized in the module 300.

In FIG. 20C, a tuned RF shield 102 is shown to be formed only partiallyabout one device 310 mounted on a module 300. Such a configuration canbe implemented if RF emissions and susceptibilities associated with thefirst device 310 is sufficiently localized and directional, so that afull enclosure with shielding-wirebonds is not needed. In FIG. 20C, thesecond device 312, similar to the example of FIG. 20B, does not produceRF emissions and is generally not susceptible to interference from RFsignals or noises.

Other configurations are also possible.

In some implementations, a device having one or more features describedherein can be included in an RF device such as a wireless device. Such adevice and/or a circuit can be implemented directly in the wirelessdevice, in a modular form as described herein, or in some combinationthereof. In some embodiments, such a wireless device can include, forexample, a cellular phone, a smart-phone, a hand-held wireless devicewith or without phone functionality, a wireless tablet, etc.

FIG. 21 schematically depicts an example wireless device 400 having oneor more advantageous features described herein. In the context of amodule having tuned RF shielding with one or more features as describedherein, such a module can include a power amplifier (PA) module 300having one or more PAs, and at least some of such PAs shielded asdescribed herein. Other modules associated with the wireless device 400can also be shielded in similar manners.

In the example wireless device 400, the shielded PA module 300 havingcan provide an amplified RF signal to a switch 422 (via a duplexer 420),and the switch 422 can route the amplified RF signal to an antenna 424.The PA module 300 can receive an unamplified RF signal from atransceiver 414 that can be configured and operated in known manners.

The transceiver 414 can also be configured to process received signals.Such received signals can be routed to one or more LNAs (not shown) fromthe antenna 424, through the duplexer 420.

The transceiver 414 is shown to interact with a baseband sub-system 410that is configured to provide conversion between data and/or voicesignals suitable for a user and RF signals suitable for the transceiver414. The transceiver 414 is also shown to be connected to a powermanagement component 406 that is configured to manage power for theoperation of the wireless device 400.

The baseband sub-system 410 is shown to be connected to a user interface402 to facilitate various input and output of voice and/or data providedto and received from the user. The baseband sub-system 410 can also beconnected to a memory 404 that is configured to store data and/orinstructions to facilitate the operation of the wireless device, and/orto provide storage of information for the user.

A number of other wireless device configurations can utilize one or morefeatures described herein. For example, a wireless device does not needto be a multi-band device. In another example, a wireless device caninclude additional antennas such as diversity antenna, and additionalconnectivity features such as Wi-Fi, Bluetooth, and GPS.

Unless the context clearly requires otherwise, throughout thedescription and the claims, the words “comprise,” “comprising,” and thelike are to be construed in an inclusive sense, as opposed to anexclusive or exhaustive sense; that is to say, in the sense of“including, but not limited to.” The word “coupled”, as generally usedherein, refers to two or more elements that may be either directlyconnected, or connected by way of one or more intermediate elements.Additionally, the words “herein,” “above,” “below,” and words of similarimport, when used in this application, shall refer to this applicationas a whole and not to any particular portions of this application. Wherethe context permits, words in the above Detailed Description using thesingular or plural number may also include the plural or singular numberrespectively. The word “or” in reference to a list of two or more items,that word covers all of the following interpretations of the word: anyof the items in the list, all of the items in the list, and anycombination of the items in the list.

The above detailed description of embodiments of the invention is notintended to be exhaustive or to limit the invention to the precise formdisclosed above. While specific embodiments of, and examples for, theinvention are described above for illustrative purposes, variousequivalent modifications are possible within the scope of the invention,as those skilled in the relevant art will recognize. For example, whileprocesses or blocks are presented in a given order, alternativeembodiments may perform routines having steps, or employ systems havingblocks, in a different order, and some processes or blocks may bedeleted, moved, added, subdivided, combined, and/or modified. Each ofthese processes or blocks may be implemented in a variety of differentways. Also, while processes or blocks are at times shown as beingperformed in series, these processes or blocks may instead be performedin parallel, or may be performed at different times.

The teachings of the invention provided herein can be applied to othersystems, not necessarily the system described above. The elements andacts of the various embodiments described above can be combined toprovide further embodiments.

While certain embodiments of the inventions have been described, theseembodiments have been presented by way of example only, and are notintended to limit the scope of the disclosure. Indeed, the novel methodsand systems described herein may be embodied in a variety of otherforms; furthermore, various omissions, substitutions and changes in theform of the methods and systems described herein may be made withoutdeparting from the spirit of the disclosure. The accompanying claims andtheir equivalents are intended to cover such forms or modifications aswould fall within the scope and spirit of the disclosure.

What is claimed is:
 1. A method for fabricating a radio-frequency (RF)module, the method comprising: providing a packaging substrateconfigured to receive a plurality of components; mounting one or more RFcomponents on the packaging substrate; and forming an RF shield relativeto the one or more RF components, the RF shield including a firstsegment configured to provide a base-level of shielding, and a secondsegment configured to provide a selective-level of shielding that isdifferent than the base-level based on an RF emission pattern associatedwith operation of the RF module.
 2. The method of claim 1 wherein the RFshield includes a plurality of wirebonds that are electrically connectedto a ground plane on or within the packaging substrate.
 3. The method ofclaim 2 wherein the second segment providing the selective-level ofshielding is configured based on an emission hotspot in the RF emissionpattern.
 4. The method of claim 3 wherein the selective-level ofshielding is enhanced when compared to the base-level of shielding. 5.The method of claim 4 wherein the second segment is positioned toprovide the enhanced selective-level of shielding of the emissionhotspot for a location within the RF module or external to the RFmodule.
 6. The method of claim 3 wherein the selective-level ofshielding is reduced when compared to the base-level of shielding. 7.The method of claim 6 wherein the second segment is positioned at alocation where the reduced selective-level of shielding does not have asignificant impact from the emission hotspot.
 8. The method of claim 2further comprising forming an overmold over the packaging substrate tosubstantially encapsulate the plurality of RF components and thewirebonds of the RF shield.
 9. The method of claim 8 further comprisingforming a conductive layer over the overmold such that the wirebonds ofthe RF shield provide an electrical connection between the conductivelayer and the ground plane.
 10. The method of claim 2 wherein each ofthe plurality of wirebonds has two ends attached to the packagingsubstrate, or one end attached to the packaging substrate.
 11. A methodfor shielding a radio-frequency (RF) module, the method comprising:determining a shielding location for a tuned RF shield within the RFmodule such that presence of the tuned RF shield at the shieldinglocation selectively reduces an impact of a hotspot in an RF emissionpattern relative to the RF module; and implementing one or morewirebonds to yield the tuned RF shield at the shielding location. 12.The method of claim 11 wherein the hotspot is located within the RFmodule.
 13. The method of claim 12 wherein the impact of the hotspot isselectively reduced at another location within the RF module or externalto the RF module.
 14. The method of claim 13 wherein the hotspot isbased on a radiated power level at or near the location within the RFmodule.
 15. The method of claim 14 further comprising determining thelocation of the hotspot prior to the determining of the shieldinglocation.
 16. The method of claim 12 wherein the one or more wirebondsare configured to provide the selective reduction in the impact of thehotspot sufficiently without unnecessary wirebonds.
 17. The method ofclaim 16 wherein the tuned RF shield is an independent RF shield. 18.The method of claim 16 wherein the tuned RF shield includes amodification to an existing RF shield.
 19. The method of claim 18wherein the modification includes an increased number of wirebonds at ornear the shielding location.
 20. The method of claim 18 wherein themodification includes a decreased number of wirebonds at or near alocation away from the shielding location.